This invention relates to a dyeing process for various kinds of fibers such as silk, wool and the like.
As processes for dyeing various kinds of fibers such as silk, wool and the like, there have hitherto been known, in general, an acid bath dyeing process and a neutral bath dyeing process.
Among the foregoing conventional dyeing processes, the former one, that is, the acid bath dyeing process, is such that the dyeing of the fibers is carried out by ionic bonding, so that the process is high in degree of exhaustion of dyes and is suitable for deep shade dyeing and is excellent in fastness for dyeing. However, the process is disadvantageous in that it is low in leveling property and is liable to result in dyeing specks.
The neutral bath dyeing process is excellent in migration property and accordingly is excellent in leveling property, so that dyeing specks are not a problem. However, the process is inconvenient in that it is low in degree of exhaustion and it is difficult to obtain a deep shade dyeing, and it is poor in fastness for dyeing.
This invention has for an object the providing of a process which does not have the disadvantages described above and to provide a dyeing process for fibers that, even in a neutral bath dyeing process which is excellent in leveling property and does not cause dyeing specks, produces a degree of exhaustion which is higher than that obtained with an acid bath dyeing process and which is suitable for deep shade dyeing and can provide excellent fastness for dyeing such as that obtained in an acid bath dyeing process.